Intraoperative monitoring of somatosensory evoked potentials (SEPs) has become a standard component of many spinal surgical procedures. Large- scale studies have demonstrated that such monitoring, which assesses transmission through the dorsal columns, reduces the incidence of spinal cord damage during surgery by helping detect surgical events which compromise cord function. However, current SEP techniques, based on signal averaging in the time domain of cortical responses to transient stimulation of peripheral nerves, require 1-2 minutes or more of data collection to yield a stable signal. There is a critical need for improvements in stimulation protocols and data analysis methods to reduce this delay by application of modern digital signal processing (DSP) techniques. A new method which we have developed, frequency domain analysis of SEPs, yields superior signal-to-noise ratios in only a few seconds. The primary aim of this project is to adapt these findings for use in the operating room. This will include determining optimal parameters, and (in Phase II) implementing these techniques in a portable system. PROPOSED COMMERCIAL APPLICATION: Potential commercialization is within the established market for evoked- response equipment used for intraoperative monitoring.